I start with either a towel or small blanket, easy to remove and clean if accidents, puke, etc gets on it.
Also much less for them to eat if they feel so inclined
Once they've proven trustworthy I usually give either a full size blanket or bed in the crate depending on what the dog prefers.
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010